You don't need ASICs to mine bitcoin. You can use video cards or FPGAs and mine the most profitable coins. NiceHash and similar services will mine the most profitable coin and pay out rewards in bitcoins, or other coins from their list. You can use video cards in an apartment, unlike asics.
This is wrong. To mine Bitcoin efficiently, you need ASICs.
Mining another coin on another algorithm (I mean other than sha256) and getting paid in Bitcoin is not mining Bitcoin. You won't be contributing to the Bitcoin Network's global hashrate if you are mining this way.
I've got nothing against using Nicehash -even if their way of playing both sides is a bit dubious- but we can't say we don't need an ASIC to mine BTC, it's a mistake.