1202 exclusion, 28% tax on unexcluded gain

Taxpayer sold QSBS in 2020 with substantial gain. He meets requirements and is qualified to exclude 50% of the gain. Based on the tax code, the unexcluded gain should be taxed at 28% rate.
I read the schedule D instruction, and it says if line 15 and line 16 of schedule D is negative, no need to fill out line 18 which shows amount from 28% rate gain worksheet.
But I am confused about the logic behind this:
Why should the 28% tax be ignored if the 1202 gain produces capital loss?
Or Am I missing something?
Will the gain be included in the future year when taxpayer has capital gain?
Thank you!

So there is an overall capital loss, right? Taxpayer must have also sold something else that had a loss exceeding 50% of the QSBS gain, right? You can offset the two.

There is no "unrecaptured 28% collectible capital gain" that will come to life in future years when there is another capital gain.

What taxable year is involved?

So there is an overall capital loss, right? Taxpayer must have also sold something else that had a loss exceeding 50% of the QSBS gain, right? You can offset the two.

There is no "unrecaptured 28% collectible capital gain" that will come to life in future years when there is another capital gain.

Thank you for the help!
Yes, there are other transactions which generate loss and the net of all gains/losses (including the 28% QSBS gain) is a loss.
So, there is no need to calculate the 28% tax on the unexcluded QSBS gain in this scenario, right?
If the net is a gain, the 28% tax rate worksheet needs to be filled.

What taxable year is involved?

The QSBS stocks were sold in 2020 tax year.

And acquired on what date (which is what I should have asked)?

And acquired on what date (which is what I should have asked)?

Some were acquired in 2008 and some in2011..

Got it. So you are only asking about the 50% exclusion ones.