As an EA group facilitator, I've been a part of many complex discussions talking about the tradeoffs between prioritizing long-term and short-term causes.

Even though I consider myself a longtermist, I now have a better understanding and respect for the concerns that near-term-focused EAs bring up. Allow me to share a few of them.

1. The world has finite resources, so when you direct resources to long-term causes, those same resources cannot be put towards short-term causes. If the EA community was 100% focused on the very long term, for example, then it's likely that solvable problems in the near-term affecting millions or billions of people would get less attention and resources, even if they were easy to solve. This is especially true as EA gets bigger, having a more outsized impact on where resources are directed. As this post says, marginal reasoning becomes less valid as EA gets larger.
2. Some long-term EA cause areas may increase the risk of negative outcomes in the near-term. For example, people working on AI safety often collaborate with and even contribute to capabilities research. AI is already a very disruptive technology and will likely be even moreso as its capabilities become more powerful.
3. People who think "x-risk is all that matters" may be discounting other kinds of risks, such as s-risks (suffering risks) due to dystopian futures. If we prioritize x-risk while allowing global catastrophic risks (GCRs) to increase (that is, risks which don't wipe out humanity but greatly set back civilization), that increases s-risks because it's very hard to have well-functioning institutions and governments in a world crippled by war, famine, and other problems.

These and other concerns have updated me towards preferring a "balanced portfolio" of resources spread across EA causes from different worldviews, even if my inside view prefers certain causes over others.