“Which questions are important?”

Suppose a journal repeatedly publishes:

50 articles about colonialism

but only:

2 articles about medieval taxation.

The journal is therefore providing much greater scholarly attention to colonialism.

But notice something important:

It doesn't necessarily mean the journal has explicitly declared:

“Medieval taxation is unimportant.”

The effect can occur through accumulated choices.

“That influences what researchers perceive as worthwhile.”

What does “that” refer to?

It refers to the pattern of institutional attention.

Imagine a young historian thinking:

“What should I research for my PhD?”

They observe:

colonialism receives many conferences;

colonialism has many journals;

colonialism attracts funding;

colonialism has many specialists;

colonialism produces academic jobs;

colonialism is frequently discussed.

They may conclude:

“This is an important and promising research area.”

That is why it becomes worthwhile.

“Worthwhile” here means:

likely to be regarded as intellectually significant, publishable, career-relevant, fundable, or capable of attracting scholarly attention.

It doesn't necessarily mean:

morally or intellectually more valuable in an absolute sense.