Bitcoin is not a cryptocurrency don't mislead newbies here bitcoin is bitcoin while shitcoins is shitcoins moreover this is a bitcoin discussion thread so you can take your Crypto elsewhere.
Unless you are advising investor or newbies not to invest into shitcoins rather than bitcoin investment which their discretionary income and hodl bitcoin for long either using the DCA strategy to stack bitcoin buying either weekly or monthly and hodl rather than fucking around shitcoins.
Personally, if you say that Bitcoin is not part of cryptocurrencies, I think that assumption is also inaccurate. Because as far as I know, those that use blockchain technology or cryptography can be said to be part of crypto currency. So bitcoin can also be called part of crypto, because bitcoin also uses blockchain technology and in fact bitcoin is the one who pioneered it. But what differentiates bitcoin from other cryptocurrencies is its quality alone. Because it cannot be denied that what we call shitcoin has quite bad quality. So it wouldn't be good if used as an investment. In contrast to bitcoin, bitcoin has a decentralized system and also has a high level of security that will be difficult for any cybercriminal to penetrate. That's why bitcoin is superior to shitcoin. And it's true that instead of trading in shitcoins, it's definitely better to invest in bitcoin. Because investing in bitcoin has very minimal risk and playing with shitcoins is very risky. So we really have to stay away from shitcoins and keep investing in bitcoin.
You are making sense though but the truth is Bitcoin is still a part of cryptocurrency but for the sake of newbie here it won't be good to be addressing it as a cryptocurrency because this can make them to invest in shitcoin thinking that they are all same thing which may result to a loss or gain depending so it will be wise if we don't classified or categorize Bitcoin in cryptocurrency. However, one of the difference you didn't mentioned that makes Bitcoin so special is the potential of it and not just quality as you mentioned because
some other shitcoin has quality and no investment is risk free but the risk in Bitcoin investment is very minimal and if you should hold for a long period of time with consistent accumulation you will make a good return.
What quality does some other shitcoins have when they are all dependent on Bitcoin? All shitcoins are just shitcoins, there is no specialty to any one they are all the same and should be treated the same way, we don't have to get confused about this, the truth can be bitter

You are correct Stormisover. We have to treat each shitcoin with a presumption that they are shit, which largely means that if we want to overcome such presumption that they are shit, then it would take a lot of studying into them in order to show the extent to which they have any qualities, which still does not mean that we would invest in them merely because they have some qualities... yet we should not be presuming them to have qualities.. that is not necessary and many times distracting to try to figure out which shitcoins happen to be less shitty, which also can be deceiving.
When it comes to something like a protocol (which bitcoin is), any competitor that may want to dislodge a protocol has to be something in the ballpark of 10x or more better than the protocol in order to dislodge it.. .. It cannot be merely "arguably" better and blah blah blah...so for sure, many times shitcoins tend to be quite ambiguous in the various ways that they are supposedly equal to or better than bitcoin, and so we need to continue to look at them (to the extent that we waste time looking at them) with considerably large grains of salt of skepticism, since many of them are just leaching off of bitcoin, deceiving people, printing money for insiders and other scandalous and vaporware behaviors, as you already suggested.
What quality does some other shitcoins have when they are all dependent on Bitcoin? All shitcoins are just shitcoins, there is no specialty to any one they are all the same and should be treated the same way, we don't have to get confused about this, the truth can be bitter

If it was like that, there wouldn't be that much capital inside of them

Don't get distracted into believing that shitcoins have value merely by the fact that retards (including the USA president) and other seemingly smart and/or influential people, governments and/or institutions are pumping shitcoins (or certain stable coins). If you cannot understand and/or appreciate how bitcoin is different, you likely need to continue studying bitcoin first before giving any benefit of the doubt to various scams that are likely going to help you to lose money and/or prevent you from investing into bitcoin as much as you would have (or could have) otherwise accomplished if you had not been distracted.