Can the blockchain be outpaced by a chain of low-difficulty blocks? Let's say someone creates a blockchain fork starting from the genesis block, when the difficulty was absurdly low compared to today; then he starts mining new blocks from there up to the current block index.

Normally, this would require such an amount of time to make it completely impossibile to catch up with the real blockchain; even if he used today's powerful mining hardware, the difficulty increase would compensate for it quickly. But, here's the catch: he customizes his mining software to not ever increase the difficulty, even if it's mining hundreds of blocks per second; block timestamps are simply faked in order to make it seem they were generated at ~10 minutes interval.

When the fake blockchain is longer then the real one (currently ~300000 blocks), he starts broadcasting it; it appears to conform to all rules, and it's longer than the current one, thus all clients and miners treat this as a winning fork and switch to working on it. Of course, difficulty increases abruptly as soon as the full network hashing power is thrown at it, and after some time block generation resumes normal levels.

But now the creator of the fake blockchain owns all Bitcoins that have been generated from the genesis block to when he released it.

Is this scenario actually possible? If not, why? How would Bitcoin nodes reacts to a 300000-blocks-long fork? Is there a limit on how long a fork can be?
There are two problems with this:


The "longest" block chain is selected not by total number of blocks, but by total difficulty.  A chain with a large number of low-difficulty blocks would not win.
The Bitcoin reference client hard-codes the hashes of a relatively recent block as a "checkpoint" and will reject any chain not containing that block at the correct height.  So any chain that diverges before the checkpoint will be ignored.