That is right. But if the bitcoin or another coin such as Zcash are in active development and used widely, the price will rise.
Active development of certain coin is just not valid argument for investing in them. It won't guarantee that users will be interested and coin will be adopted.
There are shitload of altcoin and most of them are in state of 'active development. Coins need to earn certain amount of reputation before it can be recognized first.
Bitcoin due to fact that its reputation as the oldest cryptocurrency, reliability and proven longevity (at least compared to other coins) is the obvious choice for investors and hodlers.