Clearly, some members of Congress had questions about whether Ohio's electoral votes were "regularly given"--specifically, whether the election (and subsequent recount) in Ohio was held in accordance with all Ohio and federal laws.
Given that they had those questions, it was their duty to object to the votes and to call for a discussion.
They were doing their job. Anybody who suggests they should have ignored their own doubts just to make the process run more smoothly is not really interested in fair elections.
And for what it's worth, the fact that only Ohio was challenged is absolute, undeniable proof that this was NOT about changing the outcome of the election--even if Ohio's votes had been rejected, Bush would have won, 266-251. There was no alternate slate to allow, so there would have been only 518 votes cast, and only 260 would have been required to win. The other states that might conceivably been contested had already been passed over.
Here is a problem with the idea of challenging Ohio on the basis that the votes were not "regularly given".
If there were discrepancies in the way the election was held compared to the law, it seriously looks to me like the discrepancies were minor, isolated, and had no bearing on the outcome of the election. To me, there simply is not enough to warrant a challenge.
If we accept that any violation of election law no matter how small or inconsequential to the outcome is allowed to be the basis for a challenge, we are opening up a Pandora's box that I think the country can ill afford. For instance, in my state there is a law that says campaign signs can be no closer than something like 50 feet from the entrance of a polling place. Suppose by accident some precinct measures wrong and allows signs 45 feet from the entrance. Now we have an illegal election, which by today's precedent and by the quoted argument, would be fair game for being challenged in the Joint Session. This can only lead to disaster.
In fact, what may happen is election workers will intentionally violate inconsequential parts of the law just to create grounds to challenge the election later.
In my view the challengers in Congress were derelict in their duty to the country. They were willing to undermine the entire democratic process in order to attempt to make political points. That is just awful. If there are ways to make the election process better, risking our democratic underpinnings to do it is irresponsible. There is a better place and time to make their point.
Now had Ohio's votes actually been thrown out, I don't agree that this would have simply reduced the number of appointed electors. I think it would have thrown the election to the House.