You mean, Democrats only wanted people who were interested in investigating Trump.
Democrats (and two Republicans) are interested in investigating the events and people surrounding the attack on the Capitol building Jan 6. This will implicate Trump and his co-conspirators such as Stone, Flynn, Bannon, and Giuliani.
The Republicans have put forth aspects of the capitol attack that they would like to see investigated by the committee that the committee is not investigating.
Perhaps they shouldn't have withdrawn their three acceptable submissions and forfeited the other two choices to Pelosi by not suggesting two others to replace the two rejected. Since they didn't, Pelosi got to choose how many and which Republicans would serve on the committee to serve conservative interests. They're both quite conservative, and both voted with the majority of the party on most votes. The rest of the Republicans don't object to them because they are conservative Republicans, but because they will not support the party's effort to thwart the investigation. The party objects because they are interested in getting to the truth, which will be very embarrassing for many of the rest of the Republicans.
I don't care what the composition of the committee is as long as it is sincere in attempting to get to the truth of Jan 6. If the Republican leadership doesn't want to participate, that's fine.
Please realize this: bipartisanship refers to the cooperation of competing political parties that share common (American in this case) values, but with a different idea of how to do that. They both want to provide for the common defense, but one think that means thorough forming alliances and the other through isolationism. The both want people to have equal rights and opportunities, but one thinks that includes affirmative action and the other doesn't. In such a setting, each party can see the other as the loyal opposition.
But those who do not share these core American values are simply unwelcome to participate. How many entities that want to see American democracy taken down are there in the world? None of them are invited to participate. The input of none of them is solicited. Such entities include Russia, China, Iran, Afghanistan, North Korea, and now, the bulk of the Republican party, which like the others, has no use for Americanism or the Constitution - no use for democracy or the rule of law.
They're simply all unwelcome to participate, and the duty of all loyal Americans is to neutralize their pernicious influence as much as possible. Pelosi did that. Even Cheney and Kinzinger were on board with that thinking. They are both good examples of the loyal opposition, and they make the committee bipartisan.
The entire point of a committee is delegation.
The point of this committee is investigation.
The committee does not represent the interests of roughly half of congress (and by extension roughly half the country).
As was asked of the German who complained that he couldn't find a good bagel anywhere in Berlin, whose fault is that?