Bitcoin Development Is Beyond Slow! IMHO! Yell at me! Prove Me Wrong! :)

[pooya87]

Suppose an incompetent developer would push an arbitrary change, miners will think twice before adopting it.

Again this has little to do with size and mostly it is about decentralization.
In a centralized altcoin a change is "pushed" however in a decentralized bitcoin the changes are "proposed" and that's just the start. After that the proposal is discussed and usually get improved or changed then implemented and then starts being tested to find weaknesses and improve some more or maybe even reject at this point.
After all of this is done, it is put forth for users to accept (nodes upgrade to the new version and miners signal for the new change). If an incompetent developer proposes any bad change it would be rejected at the very beginning. This process has been in bitcoin from the beginning when bitcoin wasn't worth anything. Even Satoshi didn't just "push" changes, they were discussed and reviewed in that small community back then with Hal Finney et al.
BTW this is why OP is calling this process "beyond slow".

[zeuner]

Suppose an incompetent developer would push an arbitrary change, miners will think twice before adopting it.

Again this has little to do with size and mostly it is about decentralization.

Again, this has also something to do with size, no matter how often you claim it doesn't: With a small market cap, there is nothing at stake, and even if the community somehow managed to reach some degree of decentralization, miners still don't have much to lose if they adopt some random change and possibly risk a blockchain split. Since there is much at stake for Bitcoin, people do actually care about avoiding a blockchain split. This leads to being conservative about changes that are adopted.

You have to observe these systems as a whole in order to understand them. There is no such thing as an Altcoin that is just decentralized, with no other characteristics being relevant.