Charles Babbage is considered the father of modern computers because he conceptualized and designed the first mechanical computer, known as the Analytical Engine, in the 1830s. His design included features such as an arithmetic logic unit, control flow through conditional branching and loops, and memory, which are fundamental components of modern computers. Although the Analytical Engine was never completed in his lifetime, Babbage’s ideas laid the groundwork for later developments in computing.

Fragmentation has the following demerits:

1. Increased Overhead: Fragmentation can lead to higher overhead as the system must manage multiple pieces of data instead of a single contiguous block.

2. Reduced Performance: Accessing fragmented data can result in increased seek time and latency, reducing the overall performance of data retrieval operations.

3. Resource Waste: Fragmented memory can lead to inefficient use of resources, as small unusable gaps are created between fragments, leading to wasted space.

4. Complexity in Management: Fragmentation complicates memory management and allocation strategies, often requiring sophisticated algorithms to handle memory requests.

5. Higher Risk of Memory Exhaustion: As the memory becomes fragmented, it may become more challenging to find contiguous blocks of memory, leading to potential out-of-memory errors even when sufficient total memory exists.

6. Increased Latency in Data Retrieval: For storage systems, fragmentation can increase the time needed to access data, as the read/write heads must move to different locations on storage media.

7. Challenges in Scaling: Fragmented systems may face difficulties when scaling up, as the non-contiguous memory allocation can hinder performance improvements and upgrades.

Understanding these demerits can help in designing better systems that minimize fragmentation and its negative impacts.