The job of a congressional staffer is to ensure reelection so we spend almost our time getting the member on the most powerful committees (for more campaign contributions) and getting on tv (for free media).
Committees do spend more time on the content of bills but each member usually only has one staffer for multiple committees and they are still told how to vote by the party.
I wasn't 23 years old when I was writing these summaries. I was 21. There was no one in the office over 30, and no lawyers.
That does not imply that no one reads any bills. As a change to the tax code, the Section 174 language we’re all talking about was read by at minimum the (very capable) professional staff of the Joint Committee on Taxation and the CBO, for purposes of scoring the revenue impact of the bill.
The impacts of the Section 174 changes are in fact intentional, done to change said scoring. Whether or not they would be popular was not the point; all changes to the tax code are unpopular to someone. The point was to find a configuration of changes that could pass both houses at that time and get signed. That usually means a few big-ticket changes, and then lots of monkeying around with other things (like R&D) to offset those.
Nobody should be subject to a corpus of rules too volumous for them to read and understand.
It's absolutely unforgivable that legislators don't even read the laws they pass.
Sure, bugs happen. But in a system that holds immense power over people's lives, we should be striving for the level of bugs to be similar to life critical safety systems and not some glitchy business website.